In general, software technology that provides a service of a large-capacity collective memory is used for the purpose of improving efficiency of whole data processing by reducing input/output processing times in a system when there is an explosive increase in the volume of a memory used in a high-performance computing environment requiring real time/semi-real time centralized data processing.
The software technology providing the large-capacity collective memory service can be classified into three access methods according to a characteristic of a memory technologically provided on a system memory layer architecture.
A first method is to achieve magnification of a small-capacity off-chip memory (e.g., a DRAM) itself. This method is characterized in depending on new hardware as an access method to solve a problem of a size while maintaining the performance of an existing system memory. Further, a multi-node system (e.g., a cluster system and a cloud system) is limitative in that the large-capacity collective memory service cannot be extended to all memory layers of the system but confined to a node region.
A second method is to add a new large-capacity collective memory layer capable of reducing an access time interval between an off-chip memory layer and a storage device layer depending on a hardware characteristic. In general, an existing method is the technology that provides a new large-capacity swap memory layer interworking with an in-system swap mechanism (e.g., TeraMem) and can also be applied to even the multi-node system. However, this memory layer causes a processor of a single node using the corresponding large-capacity collective memory service to have a load of a context exchange caused due to a swap and has a problem in maintaining a share mechanism layer apart from the memory layer when a processor managed for each node intends to share the memory as the memory in the multi-node system. As technology similar thereto, there is a method (e.g., vSMP Foundation of ScaleMP) of collecting nodes of the multi-node system, virtualizing the nodes as single abstractive hardware and driving a single system image on a virtual system. This method is advantageous in providing a single memory viewpoint similarly to an existing system by collectively virtualizing memory resources of multiple nodes, but limitative in system extensibility due to a large load depending on virtualization.
A third method as a method for improving an access time itself of a storage device corresponds to disk cache technology (e.g., MVP of RNA networks) as the multi-node system. This method as a method of configuring a global disk cache as the multi-node system by collecting some memories of the system is suitable for an existing storage device based data centralized service, but causes an additional input/output load through the storage device in burst type large-capacity stream data processing.